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Old Jan 27, 2013, 05:46 PM
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Australia, ACT, Kambah
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Is pitch speed relevant for gas?

Hi folks, lots of electric experience but just starting in to gas with a used 77" CMPro Extra 330l and most likely a DLE-55.

I've been wondering what sort of speed to expect because it's a big factor in required servo torque. I saw the post in another thread about the 125-132mph Revolver with a DLE-55 and a 20x12 IIRC. The DLE-55 specs say max power at 7500 rpm and useable rpm up to 9000. At 9000 rpm, pitch speed is only 103mph. I understand that props can drive an acft a bit faster than pitch speed, but 25% faster?

I gather that with a 22x8 I should expect about 7500 rpm static, but even if it unloads in flight to 9000 rpm, that's less than 70mph. Now 70mph is not a problem - it's heaps fast enough, but I had the impression these 1/4 scale gassers were a bit faster than that.

What am I missing here?
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